1. Technical Field
The technology relates to a tire condition monitoring method and a tire condition monitoring system for monitoring tire conditions.
2. Related Art
Systems exist for monitoring tire conditions. For example, tire condition monitoring systems exist that include a sensor module having a sensor that is disposed in a tire and that detects a physical property value of the tire, and a transmitter that outputs the physical property value acquired by the sensor; a receiver that receives information output from the transmitter; and a monitoring device that monitors a tire condition based on the information received from the receiver. In such tire condition monitoring systems, the acquired physical property value data is sent from the transmitter to the receiver.
Additionally, in the field of communications, when communicating data, it is common practice to insert a cyclic redundancy check (CRC) in a data packet as a technology for detecting data errors (see, for example, Japanese Unexamined Patent Application No. H10-135852A). Also, as a high level of precision is required in the field of communications, in addition to the cyclic redundancy check, for example, in some cases error-correcting codes such as BCH codes or Hamming codes are used (see, for example, Japanese Unexamined Patent Application Publication No. 2002-319889).
Tire condition monitoring systems display a relatively high degree of tolerance to errors when monitoring a physical property value of a tire. As a result, currently, cyclic redundancy checks are used as a technology for detecting errors in information sent from transmitters to receivers.
By using a technology for detecting errors such as this, even if the data sent from the sensor disposed in the tire is affected by its surroundings and an error occurs in the receiver that is mounted in a vehicle, the data in error can be discovered by a cyclic redundancy check or the like and be discarded. However, in rare cases, anomalous data that differs greatly from genuine data passes through the error detecting test and is accepted as genuine data. The probability of such misdetections occurring is high, especially in tire condition monitoring systems for use in trucks that have many sensor modules. Additionally, it is possible to increase the reliability of the data by using error-correcting codes such as BCH (Bose Hocquenghem Ray-Chaudhuri codes) or Hamming codes, but in this case, the data becomes redundant and the program becomes complicated. A complicated program is a factor that leads to an increase in equipment costs of tire condition monitoring systems.